Filament-support.



J. W. HOWELL. FILAMENT SUPPORT. APPLICATION FILED 111:0. 28, 1906.

Patented 'Feb. 13, 1912.

Inventor:

dohnW.'Ho\ v H ym UNITED STATES PATENT OFFICE.

JOHN W. HOWELL, OE NEW JERSEY, ABBIGNOB T0 GENERAL ELECTRIC comm, A COEPOE-LTION OF NEW YOEK.

WEE-SUPPORT.

Specification of Letters Patent.

Patented Feb. 13, 1912.

To all whom it may concern:

Be it known that I, Jomw W. Howm, a citizen of the United States, residing at Newark, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Filament-Supports, of which the following is a specification.

This invention relates to animprovement in incandescent lamps, and more particularly to an improved means for supporting the filament and for conducting current thereto.

My invention is applicable to lam s and other apparatus having filaments'o tungsten, molybdenum, tantalum, and other refractory elements or compounds operative at high temperatures.

Tungsten lamp filaments can be satisfactorily connected with the leading-in wires of a lamp by fusing the end of the'lead-wire to the end of the filament to make what may be termed a welded joint. Such a joint is entirely free from carbonaceous paste and does not give olf any vaporizable foreign matter which might contaminate the filament during normal operation .of the lamp.

My present invention comprises a holder and current conductor support also free from paste or vaporizable material and possesses several advantages over sucha welded joint connection. ,A good electrical connection is secured between the leading-in wire and the filament without a fusing operation, and the various elements are so arranged that in case a filament becomes broken or' worn out it ma be replaced by a new filament introduce through a small hole at the top of the lamp. This renewal of the lam s may be carried out even with a relative y fine and fragile filament without any disturbance of the seals at the base of the lamp.

The details of my invention will be better understood by reference to the accompanying drawings forming a part of this specification.

Figure 1 is a perspective view showing my invention a plied to a single filament lamp; and Fig. 2 1s a detail of the filament holder.

The lamp shown in Fig. 1 comprises the usual glass envelop 1, and stem 2, and is rovided with a glass pedestal 3 supported y the stem and carrying at its to a cop er standard 4 sealed in the end 0 the g ass pedestal 3. The copper standard carries at its top a tantalum wire spring 5 of helical form to serve as a support and anchoring means for the lamp filament 6. This tantalum coil is preferably clamped or pinched in the end 0 the copper standard and is so arranged as to be subjected to transverse flexure when the filament is in place. The lower ends of the filament are clamped in the conducting supports 7 shown in detail in Fig. 2. Each support consists of a flat strip 8 of copper or other suitable metal folded back on ltself to form an eye or bend through which the end of the filament 6 passes with a loose fit. This copper stri may be welded or otherwise connected witli the usual platinum leading-in conductor 9. Aboutthe folded strip is arranged a coiled spring 10 of tantalum held in place at one end by a stop 11 and at the other end pressed against the filament to hold it tightly against the flat copper strip and insure good electrical contact between the filament and the other elements.

Even though the filament may be made of tungsten and operated at an exceedingly high temperature, the tantalum spring 10 so does not appear to combine chemically with the filament and does not in any way change the refractory nature thereof.

In case a filament becomes damaged during transportation or during normal use of 5 the lamp, the lamp bulb 1 may be opened at the top accordlng to methods now in common practice with respect to carbon filament lamps, and a new filament may be introduced throu h this small opening and may be slippef into place in the holder. No paste is required and the operation is so simple that it can readily be carried out on a commercial basis. The spring 5 normally holds the filament under tension and tends to draw the filament from the bent su port 8, but the tantalum spring 10 yieldlngly holds the filament in contact with the bend or eye and thus resists the disengaging action of spring 5. If the tension on the filament becomes excessive, as for instance, by carelessness of the operator in mounting the filament, the filament, being held in position only by'frictional engagement due to the lateral pressure of the spring 10 thereon, will slip through the holder 8 so as to relieve the excess tension.

Although I have shown a single filament lamp, my invention is applicable to lamps having more than one fi ament or loop, as will be readily understood.

What I claim as new and desire to secure Letters Patent of the United States, is:

1. The combination of a filament, su porting means therefor through which t e filament asses, and a refractory metal spring yie dingly ressing the filament laterally against sai supporting means and holdmg the filament 1n position by frictional enga ement.

2. In com ination with a filament, a conductive strip embracing said filament, and a tantalum spring yieldingly pressing the filament-laterally against said strip and holding the filament in position by frictional engagement.

3. The combination of a filament, a conductive sup rt engaging therewith, anda tantalum w i e sprmg yieldingly pressing the filament laterally against said supgort and holding the filament in position by ictional engagement.

4. The combination of a leading-in conductor, a strip connected therewith and folded into a bend, a filament passing through said bend, and a helical sprin surrounding said strip and holding sai filament in place.

5. The combination with a filament, of supporting means removably connected therewith, and a refracto spring contacting with said filament and olding it against said supporting means.

6. The combination with a filament, of supporting means detachably connected therewith, and a tantalum wire ressing against said filament to insure e ectrical connection between said filament and said supporting means.

7. The combination of a fr ment, means fon holding said e metal filaament under tension during normal use, and current-supply means detachably clamped to said filament and by frictional engagement with said filament resistin the normal tension on said filament of said olding means.

8. The combination of a fr 'le metal filament, means for normally hol ing said filament under tension, current-supply means, and a spring normally insuring contact betweens'aid ament and said current-supply means and by the friction of said contact resisting the normal tension on said fila-' ment 0 said holding means.

9. The combination of a metal filament a supporting member throu h which the filament passes, a spring ten to draw said filament from said member and a second spriin hojllding saild filament intsaid member an ictiona emen preven the wili hdrawal of out by the hil s mal tension of said spr' 10. The combination 0 aleading-in conductor, a strip connected therewith and folded into a bend, one end of said strip being bent outward to form an abutment a filament passing throu h said bend, and a helical spring surroun said stri and compressed between said ament and abutment so as to retain the filament in lace.

11. The combination of a fr 'le ament, current supply means with which said filament is'lin contact, means for holding said filament under tension durin normal use which tends to disengage said ament from said current su ply means, and resilient means for resistmg the disengaging action of said holding means.

In witness whereof, I have hereunto set my hand this 24th da of December 1906.

J0 w. HOWELL.

-Witnesses:

S. N. Wnrmmnm, Jenn J. FAGAN. 

